|Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
|Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
|Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.
|Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
|Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
|Likelihood of Avalanches
|Natural and human-triggered avalanches unlikely.
|Natural avalanches unlikely; human-triggered avalanches possible.
|Natural avalanches possible; human-triggered avalanches likely.
|Natural avalanches likely; human-triggered avalanches very likely.
|Natural and human-triggered avalanches certain.
|Avalanche Size and Distribution
|Small avalanches in isolated areas or extreme terrain.
|Small avalanches in specific areas; or large avalanches in isolated areas.
|Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
|Large avalanches in many areas; or very large avalanches in specific areas.
|Very large avalanches in many areas.
A skier triggered an avalanche in the Goldpan area two days ago, which we suspect failed on the layer of surface hoar that was buried on 11/13. More details in this observation.
|Size (D scale)
|Unlikely to bury a person
|Can bury a person
|Can destroy a house
|4 & 5
|Can destroy part or all of a village
While some parts of Southcentral will be getting hit hard by northerly winds today, it is looking like our core advisory area around Girdwood and Turnagain Pass will see another day of quiet weather. The main avalanche concern for today will be the lingering possibility of triggering an avalanche on one of two buried weak layers of snow. While these are both lumped into our ‘Persistent Slab’ problem, they have some very different characteristics.
The older snow that was buried by the 11/9 storm produced a large avalanche just over a week ago in the Goldpan area behind Magnum Ridge. This layer exists above around 3000-3500′ and becomes more problematic at higher elevations. The most likely place to encounter this layer will be in steep and rocky terrain in these upper elevations. If you haven’t already checked it out, be sure to take a quick look at this observation to see what that layer is capable of.
The other layer of concern is a layer of surface hoar that was buried on 11/13 and likely was the culprit for another skier-triggered avalanche in the Goldpan area two days ago (details here). The distribution for this layer is trickier to nail down. Despite seeing widespread surface hoar just before it was buried, it only appears to remain reactive on isolated slopes. This spotty distribution is common for buried surface hoar problems, and it really requires a slope-by-slope assessment if you are trying to get into steep terrain. The best way to manage the problem entirely is by avoiding steep and consequential terrain, especially at higher elevations where the weakest snow developed before it was buried a week ago.
We continue to see reports of glide avalanche activity from Girdwood to Summit Lake. Be sure to limit any time spent below open glide cracks, since the timing of glide avalanches is impossible to predict.
Yesterday: Temperatures barely made it out of the single digits in most areas yesterday, with clear skies and calm to light winds around 5 mph. There were some lingering valley clouds along the Turnagain Arm, with no precipitation.
Today: Temperatures remain in the single digits above and below zero this morning, but will start to climb through the day into tonight. Expect to see daytime temperatures in the low to mid teens F, and continuing to rise into the low to mid 20’s F tonight. Cloud cover will increase through the day as well, with a trace of precipitation possible tonight and rain levels around 300-500′. Winds should remain light for Girdwood, Turnagain Pass, and Summit Lake, but will be 15-25 mph in Seward with gusts up to 50 mph in the front range.
Tomorrow: Light precipitation will begin tomorrow and continue through the week. We will likely only see 1-2″ snow tomorrow, with rain levels increasing to 1100-1300′ through the day. Winds should remain light out of the east around 10 mph, with high temperatures in the high 20’s to low 30’s F, and overnight lows in the low to mid 20’s F.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)
|Snow Depth (in)
|Center Ridge (1880′)
|Summit Lake (1400′)
|Alyeska Mid (1700′)
|Bear Valley – Portage (132′)
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)
|Wind Avg (mph)
|Wind Gust (mph)
|Seattle Ridge (2400′)
|Observation: TinCan Backdoor/ Center Ridge
|AAS L1 Turnagain
|Avalanche: Lynx Creek
|Observation: Turnagain, Seattle, Mt Ascension
|Silverton Mountain Guides
|Observation: Tincan Trees
|Dalpes/Thamm/ Schauer Forecaster
|Observation: Seward Highway across from Johnson Pass TH
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek
|Observation: Tincan Trees
|Moderow / Clayton